I'm in the middle of building an earth covered ICF home in southern Mississippi and am loking for some advice on waterproofing.  The entire structure is above the original site grade but will be covered with two feet of earth on top of the house then tapered out at about a 4/12 grade.  I've used Cellox ICF's with 12" vertical walls and Insuldeck forms for the roof with 10.5"beams and a 5"slab.  I have already purchased Platon for the vertical walls and am installing a foundation drain around the perimeter.  I am looking for some advice on the need for sealer on the walls as well as the essentially flat roof(1"/10' fall).  Do I need a sealer on the walls in addition to the platon?  On the roof I'm looking at a simple layer of tar.  The tar would be followed by a 6" layer of gravel capped with 6" of compacted clay prior to topsoil.  I'm planning a similar arrangement on the vertical walls with a layer of gravel back fill next to the Platon with compacted clay adjacent to that.  Does anyone have any experience or advice on this topic?  Can anyone recommend a good spray, roll or trowel on membrane?  I am the labor as well as the engineer, designer and contractor.

I would look at using a spray on or roll on water based membrane OR a peel and stick for both wall and roof, walls first then roof, overlapping the walls.

Then dimple membrane (Platon) on the walls and EPDM (rubber membrane) over the roof, hanging over the walls. I would maybe mound pea rock, insulation or something over the peel and stick of the roof to create a dome, and put the EPDM on that to shed water. Don't use any back-fill that could damage your membrane, no frozen fill, roots or sharp rock.

This redundancy maybe overkill but relatively cheap compared to have to fix this latter. You don't want leaks.

I would be careful using the tar on the roof, while tar is meant for a water proof, it is not meant to sit in water. I have seen many built-up flat roofs, above grade, that because water sat on it all the time the tar rotted. There was a trend in the seventies to keep water from draining off flat roofs, it was because the evaporating rainwater keep the roof and inside cooler. They discovered the tar rotted when it sat in water that long. That may happen on a horizontal surface below grade.

Can you recommend a water based membrane that is available for sale in the southern us?  Everybody around here looks at me like I'm crazy when I ask if they carry something.

I am from the great white north, but I you should be able to get peel and stick at your Home Depot or similar. Or better yet check with your ICF /Insul-Deck distributor.

If you are having difficulty finding it, try a roofing supply store and ask for Grace 4000 and the primer

Please do not use tar as your roofing. 

I am not much help in the DIY roofing department, but I would be looking at a product like Hydrotech 6125 (hot applied "rubber") or a good sheet product. 

In any case, do a flood test after your roof installation and use a protectiion board between the membrane and the backfill.

You might consider a hydrophobic admix or coating to your concrete as a "belt and susenders" approach, but I would not rely on hydrophobic material as your primary water defense.

Bruce

Having thought about it a bit more, if you have not poured it yet, consider increasing the slope of your roof to 1.5 or 2%.

Where will the water drain to?  Over the edge of the roof?

What you are really building is an intensive green roof. You should really think about adding a root barrier to your roofing system, too.

Bruce

WE HAVE TWO OPTIONS, IF YOU DO IT YOURSELF SEE IF YOU CAN LOCATE A SUPPLIER FOR W.R. MEADOWS, THEY MAKE A LIQUID ,WATERBASED MEMBRANE ( MEL -ROL LM)THAT YOU CAN SPRAY OR ROLL ON. IT COMES IN 5 GAL BUCKETS USELY COVERS AROUND 150 SQ/FT DEPENDING ON HOW YOU APPLY IT. WE FILL ANY CRACKS, JOINTS, WITH SPRAY FOAM,WIPE IT FLUSH WITH THE WALL AND APPLY TWO COATS OF MEL- ROL LM, WITH 1" FOAM BACK FILL BOARD .THE OTHER OPTION IS SEE IF THERE IS A MARFLEX REP, OR INSTALLER IN YOUR AREA. THEY OFFER A TWENTY FIVE YEAR WARRANTY. THEY PREP, SPRAY ON A LIQUID MEMBRANE, INSTALL PLATON BOARD. IN ALL THE YEARS I'VE BEEN INSTALLING ICFS THEY DO A GREAT JOB. BUT THERE AGAIN IT DEPENDS ON THE INSTALLER.

GRACE MEADOWS WEBSITE---www.wrmeadows.com

TODD